Methods and devices for reprocessing used plastic containers are known. In most cases the labels are released and removed as the first step. Then in a next step a mill is used to pulverize the containers to flakes. The resulting mixture is washed and cleaned to remove any remaining residues of glue. Then the flakes are separated according to different types of plastic, e.g., PET and polyethylene.
Next, the flakes are cleaned in a decontamination step so that they can be reused to produce new plastic containers.
Thus for example, a decontamination process in which PET flakes from pulverized beverage bottles are subjected to a washing treatment in a washer is known from DE-10002682. Furthermore U.S. Pat. No. 5,688,693 describes a method in which highly contaminated bottles or flakes are identified and removed from the reprocessing operation.
However, the known processes are based on the problem that the decontamination process step of the reprocessing operation is adjusted to worst case conditions which means that the cleaning process is always performed, regardless of the degree of soiling of the starting material, in such a way that even the most contaminated plastic bottles and/or plastic flakes are adequately cleaned. Therefore, these known methods are not economical, even when an adequate cleaning is achieved.